The following definitions apply to the sound insulation coefficient for separating solid components:
Rw = weighted sound insulation coefficient without taking into account the flank transmission in dB. Only direct sound transmission via the separating component is taken into account. It is the measure of the acoustic performance of the component, e.g. a sand-lime brick wall plastered on both sides.
R'w = weighted sound insulation value with consideration of the flank transmission in dB. All possible transmission paths of the finished wall between two rooms are taken into account, i.e. also the sound behaviour of flanking components, whereby an average area-related mass of the flanking components according to DIN 4109 Supplement 1 of approx. 300 kg/m² is assumed. If the average area-related mass deviates significantly from this, corrections must be taken into account. R'w thus describes the resulting sound insulation as a building property.
R'w, R = calculation value of the "weighted sound insulation value" in dB with sound transmission via flanking components. It is the characteristic parameter of airborne sound insulation for proving the suitability of walls and ceilings as separating components. It results for designs according to DIN 4109, Supplement 1.
R'w, res = the "resulting sound insulation value" is the sound insulation value of the entire component calculated from the individual sound insulation dimensions of the partial surfaces (e.g. window, wall, door, etc.). For example, an outer wall including its windows.
Source: bauwion
